1.4 Investigative Psychology


So Pinizotto and Finkel’s research showed
clearly that FBI trained profilers are not consistently better at identifying the likely
characteristics of an offender. And this ambiguity as to the superiority of FBI trained profilers
comes through in all the published accounts. On some dimensions some profilers out-perform
relevant others, and on other dimensions they don’t. So what alternative approaches exist that
use the crime scene to infer something of the characteristics of the offender? Probably the most famous alternative approach is Investigative Psychology that emerged from David Canter’s
work. Now in terms of using the crime scene to tell us something about the offender, the
aim of Investigative Psychology is much the same as that of the FBI’s approach. Essentially you want to be able to tell the investigating officers something about the characteristics
of an offender from their actions while committing the crime. This will then allow investigators
to narrow down their search of suspects. However in contrast to the FBI’s approach,
Investigative Psychology attempts to identify these characteristics by analysing behaviour
in a way that is independent of the psychological mechanisms that underpin it. That is, Investigative Psychology is not focused on identifying ‘why’ the offender commits the crime. Instead, Investigative
Psychology simply infers the characteristics of the offender from the known actions taken
by the offender during the crime. With this approach, it is possible to statistically
analyse larger data sets to break down crime scenes into their component parts and then
relate these components to distinct aspects of the offender. These analyses are then submitted
for publication in peer-reviewed journals where other researchers critically evaluate
whether the analysis has been conducted according to the appropriate research practices. Unlike the FBI’s case by case approach,
analysis of large data sets in this way allows more certainty in determining how often particular
types of behaviour are seen in particular crimes. A good example of this approach is
seen in an early analysis conducted by Salfati & Canter that was published in 1999. Salfati and Canter looked at 82 British cases
of single perpetrator-single victim homicide crime scenes that had been solved. They were
interested to see whether there would be a thematic structure to the actions that occurred at these crime scenes. So they coded the information in the police
homicide files for the presence or absence of a range of variables, which reflected: * actions by the offender on the victim,
* descriptions of behaviour carried out by the offender at the crime scene * characteristics of the offender and * characteristics of the victim. Now variables that occurred in more than 90% of cases or in less than 10% of cases were excluded as they were seen to be either too common or too rare to help the classification. Salfati and Canter then analysed this data
to detect the co-occurrence of each variable with each other variable. And this analysis
allowed them to produce a visual representation of factors that frequently co-occurred and
those which were very unlikely to co-occur in this type of crime. So for example, Salfati and Canter found that
in these homicide cases, it was unusual to find a body facing up where property of value had been taken from the victim or the crime scene. Now through this analysis Salfati and
Canter identified three crime scene themes which reflect the role of the aggression in
the offence. The first of these is expressive (impulsive)
where the underlying aim of the aggression seems to be to hurt the victim. Instrumental (opportunistic) and instrumental (cognitive) is where the murder is a byproduct of other more dominant motives such as the desire for objects. Now of the 82 cases included in this analysis, 53 cases could be classified as showing a dominant impulsive, opportunistic or cognitive
crime scene theme. And of these 53 cases, 21 followed an impulsive theme of homicide crime scene behaviour. So, an expressive impulsive crime scene comprised multiple stab wounds across the victim’s body, many other types of wounds, bringing a weapon to the scene
and using a weapon from the scene in amongst other behaviours. Contrast this with an instrumental
cognitive crime scene where, for example, offenders attempted to hide their crime: either
by committing it outside or disposing of the body outside, and by removing evidence from the crime scene. Now as this analysis used solved cases, offender characteristics were known, so it was possible to see which offender characteristics co-occurred
with which crime scene behaviours. So, for example, someone whose crime scene was classified
as expressive impulsive was statistically likely to have committed prior violent or
sexual offences, prior damage to property offences and/or to have been previously married.
Those classified as having instrumental cognitive crime scenes were statistically more likely
to have served in the armed forces or had a prior prison sentence. So you can see how, as long as the perpetrator
in any given case doesn’t deviate from the ‘typical’ behaviour determined by the
analysis of data from this sample, this information would allow for a more focused targeting of
suspects. That is, if you have an expressive instrumental crime scene then, with all other
things being equal, you should start your further investigations with those suspects
who have prior charges for offences that suggest conflict with or against other people. The other notable aspect of the analysis of
Salfati and Canter is that the interactional behaviour of offenders while offending does
not seem to deviate too far from their interactional behaviour or style when not offending.
Now David Cantor, the chief proponent of Investigative Psychology, suggests that the way in which
people interact with one another in their everyday lives is so well rehearsed and ingrained
that it influences all their interactions with others, including the way that they interact
with their victim while they are offending. That is there is coherence in their personal interactions. And interpersonal coherence is one of the
factors in Canter’s five-factor model for interpreting a crime scene, which aims to
tell the investigators about the offender’s past and present experiences in life. The
second factor in this model is time and space considerations in the choice of where the
crime or crimes took place. Crime scenes are rarely random. Offenders select the time and
location of their offending for a reason. So investigators may be able to infer something
about the offender based on their choices about when and where to offend. For example, Cantor proposed that if an offender
is engaging in an offence where he needs to feel in control, then the offender is likely
to do this in a place that is familiar to him, perhaps closer to his base where he feels
more comfortable, knowledgeable and in control of what goes on. Behaviour engaged in or not engaged in at
the crime scene can also tell you valuable information about the offender’s background.
This may be as simple as an indication of the likely level of intelligence of the offender,
but it may be more detailed. For example, an offender who uses a knife in a very specific
or specialized way, might have had training in their occupation to use the knife that
particular way. This behaviour will also give you insight
into the offender’s forensic awareness, and this is the third factor in Canter’s
five-factor model. Imagine, for example, that at a crime scene it was clear that the offender
had made little effort to cover up or remove forensic evidence. This may suggest that they
do not have much experience on offending because they are not trying to evade forensic evidence
collection techniques. So this offender may have few or no prior convictions. Forensic awareness is closely related to the
fourth factor of criminal career. This is the idea that offenders will behave relatively
consistently in committing their crimes, so any previous offences committed by this offender
will resemble the current offence. Criminal career also covers the idea that deviations
or changes away from the pattern of previous offending may be in response to something
that happened while this person was attempting to commit their crime. For example, an offender
who has never drugged their victim before might drug their victims in the future because
a victim struggled in response to the attack. The final factor is criminal characteristics.
This is the idea that you can use characteristics of the offence to match it to similar types
of crime. Now an obvious question here is how does this five factor approach help us figure
out what kind of person might have committed the crime? Well once you have considered the
crime scene in light of the five-factor model of offender experiences, you can then make
inferences about the characteristics the offender might have. So this might include inferences
about the offender’s residential location, their domestic or their social characteristics,
their personal characteristics and their occupation or education history. This means that once investigators have gathered
information about the likely characteristics and experiences of the offender they will
have a description of the sort of individual who may have committed the crime. This can
help focus the investigation of the offence. Now at this point it may sound like Investigative
Psychology is very similar to the FBI’s Criminal Investigative Analysis approach.
Both seem to generate profiles of ‘typical’ offenders, which as we saw from the analysis
of Pinizotto and Finkel causes problems when your offender is in the minority that is not
typical. A key question then is how is Investigative Psychology different? Well while both Criminal Investigative Analysis
and Investigative Psychology both involve the investigator making inferences about the
offender’s likely characteristics on the basis of the crime scene, the emphasis in
each type of profile is distinct. Profiles generated by Criminal Investigative Analysis
tend to focus on an offender’s characteristics and their likely motivation. In contrast profiles
created by Investigative Psychology tend to focus on the offenders characteristics and
information about the offender’s likely location. Typically also, Canter and colleagues
research uses larger sample sizes than the FBI and subjects the research underpinning
their inferences to peer review. So Canter and Alison (2000, P1) talk of an
analysis of criminal actions from an objective, often statistical viewpoint rather than one
based on personal intuition and clinical experience. However, it is worth noting that this reliance
on statistical methods might introduce its own problems in that at best these kinds of
statistical analyses can only show associations between crime scene actions and offender characteristics.
And these associations will never be perfect, meaning that there is always the possibility
that your particular offender is an exception – a statistical outlier if you like – to
the general pattern of association seen in that type of case However, investigative psychology does suggest
a more systematic approach to working out the characteristics of the offender. So while
David Canter is most well known for profiling John Duffy, the so-called railway rapist,
since then Investigative Psychology has grown as a subdiscipline. Now, those working in
Investigative Psychology are interested in patterns of criminal behaviour more broadly,
and they can help investigators deal with a range of crimes.